A barrel of this kind is known from the leaflet of Richard Tscherwitschke GmbH, "Barrel and Superstructure Assemblies for Electroplating, Phosphating and Pickling". In such barrels charges of small metal pieces are immersed in acid or alkaline aqueous solutions, namely treatment bath solutions, where they are treated chemically or electrolytically. As a rule they stay in the treatment bath solution for at least 30 minutes, during which time they are driven at a speed of rotation of approximately 10 rpm. On this occasion a slippage results between the charge of small pieces and the inner wall of the barrel, since due to its dead weight the charge slides downwards on the inner wall of the barrel during its rotation. This gives rise to a considerable wear of the barrel coat sections, of the end faces and even of the support bars to the extent they are facing the inner room. Furthermore, the circulation movements of the individual pieces of the charge are irregular, so that a considerable scattering results during electrolytical treatment, i.e. electrolytical surface treatments, and also during chemical surface treatments, which extends the total treatment time.